The most obvious difference us the method of controlling the cant. Gen 1 I believe have a hex screw on the front that is turned to tighten the system. on Gen 2 they have a large knurled knob with holes through it that will accept a rod to assist in tightening the system and restricting or loosening the cant. The hex screw can be replaced by a handle (sold by Grey ops) that works well, but may interfere with the legs in certain positions.